1. Field of the Invention
This invention relates to a method for treating disease-related or drug-induced dyskinesias.
2. Related Background Art
Dyskinesias are debilitating motor movements that can be caused by a neurological disease, or can be drug-induced. See, for example, A. B. Joseph and R. R. Young, Movement Disorders in Neurology and Neuropsychiatry (Blackwell Scientific Publications, 1992), the disclosure of which is incorporated by reference herein. Disease-related dyskinesias can result from a wide range of conditions, including Wilson's disease, Huntington's disease and Sydenham's chores Drug-induced dyskinesias have been attributed to administration of many drugs, including drugs used in treatment of Parkinson's disease, e.g., L-DOPA, nonselective dopamine-agonists (DA-agonists), as well as DA-agonists selective for the D1, D2, D3, D4 and D5 subtypes of the dopamine receptor; and DA antagonists, especially in the case of prolonged administration of antipsychotic agents, which leads to tardive dyskinesias.
Drugs which act as non-selective antagonists of the N-methyl-D-aspartate (NMDA) receptor have been shown to decrease dyskinesias induced by administration of L-DOPA to primates suffering from 1,2,3,6-tetrahydro-1-methyl4-phenylpyridine (MPTP)-induced Parkinson's disease. The NMDA receptor comprises a NR1 subunit in combination with one or more of the NR2 subunits, NR2B, NR2C or NR2D, as disclosed in Monyer et al., Science, Vol. 256, pages 1217-1221 (1992). K. W. Muir and K. R. Lees, Stroke, Vol. 26, pages 503-513 (1995), discloses that administration of NMDA receptor antagonists that are NR1A/2B-site-selective leads to reduced psychotomimetic side-effects than administration of non-selective antagonists. S. M. Papa and T. N. Chase, Annals of Neurology, Vol. 39, pages 574-578 (1996), discloses that administration of the drug LY235959, available from Eli Lilly, Inc., reduced the severity of dyskinesia in monkeys being treated with L-DOPA. However, LY235959 is a non-selective NMDA receptor antagonist. It is not obvious from this work which subtype of the NMDA receptor is responsible for the antidyskinetic effect.
PCT International Publication No. WO 96/37226 discloses treatment of Parkinsons disease with a combination of site-selective NMDA receptor antagonist compounds and L-DOPA. Administration of the antagonist compounds allowed use of lower amounts of L-DOPA. However, there is no suggestion that NR1A/2B site-selective NMDA receptor antagonist compounds could be administered to reduce the side effects accompanying normal doses of L-DOPA.
Methods of treatment of dyskinesias with compounds which are NR1A/2B-site-selective NMDA receptor antagonists would be desirable.